anonfd: Allow making anon files read-only

It seems a couple places such as arch/ia64/kernel/perfmon.c and
drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile()
instead of a private pseudo-fs + alloc_file(), if only there were a way
to get a read-only file.  So provide this by having anon_inode_getfile()
create a read-only file if we pass O_RDONLY in flags.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Roland Dreier
2009-12-18 09:41:24 -08:00
committed by Al Viro
parent ed2617585f
commit 628ff7c1d8
7 changed files with 17 additions and 9 deletions

View File

@@ -1177,7 +1177,7 @@ static struct file_operations kvm_vcpu_fops = {
*/
static int create_vcpu_fd(struct kvm_vcpu *vcpu)
{
return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
}
/*
@@ -1638,7 +1638,7 @@ static int kvm_dev_ioctl_create_vm(void)
kvm = kvm_create_vm();
if (IS_ERR(kvm))
return PTR_ERR(kvm);
fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, 0);
fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
if (fd < 0)
kvm_put_kvm(kvm);